net: Add full IPv6 addresses to flow_keys

This patch adds full IPv6 addresses into flow_keys and uses them as
input to the flow hash function. The implementation supports either
IPv4 or IPv6 addresses in a union, and selector is used to determine
how may words to input to jhash2.

We also add flow_get_u32_dst and flow_get_u32_src functions which are
used to get a u32 representation of the source and destination
addresses. For IPv6, ipv6_addr_hash is called. These functions retain
getting the legacy values of src and dst in flow_keys.

With this patch, Ethertype and IP protocol are now included in the
flow hash input.

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 69 insertions, 23 deletions

diff --git a/include/net/flow_dissector.h b/include/net/flow_dissector.h
index cba6a10b214a..306d4613abbb 100644
--- a/include/net/flow_dissector.h
+++ b/include/net/flow_dissector.h
@@ -12,7 +12,7 @@
  */
 struct flow_dissector_key_control {
 	u16	thoff;
-	u16	padding;
+	u16	addr_type;
 };
 
 /**
@@ -28,19 +28,40 @@ struct flow_dissector_key_basic {
 };
 
 /**
- * struct flow_dissector_key_addrs:
- * @src: source ip address in case of IPv4
- *	 For IPv6 it contains 32bit hash of src address
- * @dst: destination ip address in case of IPv4
- *	 For IPv6 it contains 32bit hash of dst address
+ * struct flow_dissector_key_ipv4_addrs:
+ * @src: source ip address
+ * @dst: destination ip address
  */
-struct flow_dissector_key_addrs {
+struct flow_dissector_key_ipv4_addrs {
 	/* (src,dst) must be grouped, in the same way than in IP header */
 	__be32 src;
 	__be32 dst;
 };
 
 /**
+ * struct flow_dissector_key_ipv6_addrs:
+ * @src: source ip address
+ * @dst: destination ip address
+ */
+struct flow_dissector_key_ipv6_addrs {
+	/* (src,dst) must be grouped, in the same way than in IP header */
+	struct in6_addr src;
+	struct in6_addr dst;
+};
+
+/**
+ * struct flow_dissector_key_addrs:
+ * @v4addrs: IPv4 addresses
+ * @v6addrs: IPv6 addresses
+ */
+struct flow_dissector_key_addrs {
+	union {
+		struct flow_dissector_key_ipv4_addrs v4addrs;
+		struct flow_dissector_key_ipv6_addrs v6addrs;
+	};
+};
+
+/**
  * flow_dissector_key_tp_ports:
  *	@ports: port numbers of Transport header
  *		src: source port number
@@ -56,16 +77,6 @@ struct flow_dissector_key_ports {
 	};
 };
 
-/**
- * struct flow_dissector_key_ipv6_addrs:
- * @src: source ip address
- * @dst: destination ip address
- */
-struct flow_dissector_key_ipv6_addrs {
-	/* (src,dst) must be grouped, in the same way than in IP header */
-	struct in6_addr src;
-	struct in6_addr dst;
-};
 
 /**
  * struct flow_dissector_key_eth_addrs:
@@ -81,10 +92,10 @@ struct flow_dissector_key_eth_addrs {
 enum flow_dissector_key_id {
 	FLOW_DISSECTOR_KEY_CONTROL, /* struct flow_dissector_key_control */
 	FLOW_DISSECTOR_KEY_BASIC, /* struct flow_dissector_key_basic */
-	FLOW_DISSECTOR_KEY_IPV4_ADDRS, /* struct flow_dissector_key_addrs */
+	FLOW_DISSECTOR_KEY_IPV4_ADDRS, /* struct flow_dissector_key_ipv4_addrs */
+	FLOW_DISSECTOR_KEY_IPV6_ADDRS, /* struct flow_dissector_key_ipv6_addrs */
 	FLOW_DISSECTOR_KEY_IPV6_HASH_ADDRS, /* struct flow_dissector_key_addrs */
 	FLOW_DISSECTOR_KEY_PORTS, /* struct flow_dissector_key_ports */
-	FLOW_DISSECTOR_KEY_IPV6_ADDRS, /* struct flow_dissector_key_ipv6_addrs */
 	FLOW_DISSECTOR_KEY_ETH_ADDRS, /* struct flow_dissector_key_eth_addrs */
 
 	FLOW_DISSECTOR_KEY_MAX,
@@ -129,6 +140,9 @@ struct flow_keys {
 #define FLOW_KEYS_HASH_OFFSET		\
 	offsetof(struct flow_keys, FLOW_KEYS_HASH_START_FIELD)
 
+__be32 flow_get_u32_src(const struct flow_keys *flow);
+__be32 flow_get_u32_dst(const struct flow_keys *flow);
+
 extern struct flow_dissector flow_keys_dissector;
 extern struct flow_dissector flow_keys_buf_dissector;
 
diff --git a/include/net/ip.h b/include/net/ip.h
index 16cfc87fed6c..0750a186ea63 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -355,6 +355,20 @@ static inline __wsum inet_compute_pseudo(struct sk_buff *skb, int proto)
 				  skb->len, proto, 0);
 }
 
+/* copy IPv4 saddr & daddr to flow_keys, possibly using 64bit load/store
+ * Equivalent to :	flow->v4addrs.src = iph->saddr;
+ *			flow->v4addrs.dst = iph->daddr;
+ */
+static inline void iph_to_flow_copy_v4addrs(struct flow_keys *flow,
+					    const struct iphdr *iph)
+{
+	BUILD_BUG_ON(offsetof(typeof(flow->addrs), v4addrs.dst) !=
+		     offsetof(typeof(flow->addrs), v4addrs.src) +
+			      sizeof(flow->addrs.v4addrs.src));
+	memcpy(&flow->addrs.v4addrs, &iph->saddr, sizeof(flow->addrs.v4addrs));
+	flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
+}
+
 static inline void inet_set_txhash(struct sock *sk)
 {
 	struct inet_sock *inet = inet_sk(sk);
@@ -362,8 +376,9 @@ static inline void inet_set_txhash(struct sock *sk)
 
 	memset(&keys, 0, sizeof(keys));
 
-	keys.addrs.src = inet->inet_saddr;
-	keys.addrs.dst = inet->inet_daddr;
+	keys.addrs.v4addrs.src = inet->inet_saddr;
+	keys.addrs.v4addrs.dst = inet->inet_daddr;
+	keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
 	keys.ports.src = inet->inet_sport;
 	keys.ports.dst = inet->inet_dport;
 
diff --git a/include/net/ipv6.h b/include/net/ipv6.h
index 474ca466a091..82dbdb092a5d 100644
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -692,6 +692,20 @@ static inline int ip6_sk_dst_hoplimit(struct ipv6_pinfo *np, struct flowi6 *fl6,
 	return hlimit;
 }
 
+/* copy IPv6 saddr & daddr to flow_keys, possibly using 64bit load/store
+ * Equivalent to :	flow->v6addrs.src = iph->saddr;
+ *			flow->v6addrs.dst = iph->daddr;
+ */
+static inline void iph_to_flow_copy_v6addrs(struct flow_keys *flow,
+					    const struct ipv6hdr *iph)
+{
+	BUILD_BUG_ON(offsetof(typeof(flow->addrs), v6addrs.dst) !=
+		     offsetof(typeof(flow->addrs), v6addrs.src) +
+		     sizeof(flow->addrs.v6addrs.src));
+	memcpy(&flow->addrs.v6addrs, &iph->saddr, sizeof(flow->addrs.v6addrs));
+	flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
+}
+
 #if IS_ENABLED(CONFIG_IPV6)
 static inline void ip6_set_txhash(struct sock *sk)
 {
@@ -701,8 +715,11 @@ static inline void ip6_set_txhash(struct sock *sk)
 
 	memset(&keys, 0, sizeof(keys));
 
-	keys.addrs.src = (__force __be32)ipv6_addr_hash(&np->saddr);
-	keys.addrs.dst = (__force __be32)ipv6_addr_hash(&sk->sk_v6_daddr);
+	memcpy(&keys.addrs.v6addrs.src, &np->saddr,
+	       sizeof(keys.addrs.v6addrs.src));
+	memcpy(&keys.addrs.v6addrs.dst, &sk->sk_v6_daddr,
+	       sizeof(keys.addrs.v6addrs.dst));
+	keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
 	keys.ports.src = inet->inet_sport;
 	keys.ports.dst = inet->inet_dport;